1. Field of the Invention
The present invention relates to cellulose sponge using vegetable cellulose as raw material obtained from non-woody material like stem, leaves and seed skin of low plants, shrub, or the like, and to a method of producing the cellulose sponge.
2. Background Art
Instead of synthetic resin sponge made of foamed urethane and the like which has been conventionally used, recently sponge using vegetable cellulose as raw material has been developed and receiving attention with respect to the higher antifungal properties of the raw material and the easier disposal as waste after being use (that is, the disposal is easy such that the sponge dose not generate gas which otherwise would affect adversely environment when being incinerated). Compared with the synthetic resin sponge which has been produced with using flon (chloro fluoro carbons) gases which have bad influences on the ozone layer and accordingly been regulated, the cellulose sponge has also been receiving attention in that it can be produced with using known expanding agents without using flon gases.
Such cellulose sponge is produced by taking out vegetable cellulose from wood as raw material, and the method of producing the sponge is such that at first, the wood of the raw material is made into chip, and then the chip is dissolved to obtain pulp (cellulose). Then, the dissolved pulp is treated with a sodium hydroxide solution, and thereafter, treated by being subject to the addition of a chemical such as carbon bisulfide and sodium hydroxide to obtain viscose, which becomes liquid having somewhat viscosity. Then, the obtained viscose is mixed with an expanding agent comprising sodium sulfide and the like to expand and coagulate the mixture. Thereafter the mixture is expanded and coagulated. The expanded product obtained by such coagulation is cleaned by a softening agent, a bleaching agent, a weak acid solution and the like, whereby the above-mentioned cellulose sponge is obtained. As a post-treatment, the sponge is subject to dehydration and drying, and then the raw cloth thereof, when subject to cutting processing, is made moist and cut into lengths each of which is then packed.
Now, since recently the forest destruction has been regarded as serious, the necessity of selecting proper material instead of wood as raw material of cellulose sponge has been discussed, and thus the possibility of increasing cost has become a concerned matter.
Therefore, in the view of the above-mentioned circumstances, an object of the present invention is to obtain cellulose sponge without using wood as raw material, and an object thereof is to contribute to the prevention of the forest destruction.